- Choice of postoperative antibiotic Prescription or not postoperative antibiotic, will be determined by randomization. Before administration of the antibiotic, the patients included will be questioned on the existence of a possible allergy to beta-lactam antibiotics (CRF). The postoperative antibiotic therapy will be identical to the preoperative antibiotic therapy and include the following antibiotics: amoxicillin - clavulanate (Augmentin ® 2gx3/jour). Antibiotic treatment will be issued by pharmacies centers investigators.